Marine type superheater boiler



July 9, 1935. J, A. BARNES 2,007,267

MARINE TYPE SUPERHEATER BOILER Filed Aug. 21, 1933 2 Sheets-Sheet 1 INVENTOR L/oH/v A. BAR/v55 BY Z -ATTORNEY July 9, 1935. .1. A. BARNES MARINE TYPE SUPERHEATER BOILER Filed Aug. '21, 1935 2 Sheets-Sheet 2 Joe INVENTOR domv A. BKiR/VZS BY fl Z ATTORNEY Patented .luly 1935 PATENT .oFFieE- g o, Manner: MARINE TYPE VSUPERHEATER BOILER John A. Barnes, ChappaquauN. Y., assignor to The Superheater Company, New York, N. Y.

Application August 21, 1933, Serial No. 686,047

3 Claims. (o1.122 462) invention. relates to marine superheater boilers capable heat. r

The boilers in most common use at present in '5 the marine :service are of the'so-called'scotch I type having outer cylindrical shells, internal furnace'flues, return smoke'tubes and combustion chambers connecting the furnace flues with the return tubes. In such boilers, two types of superheaters have beenprinicpally employed. Onetype ofsuperheater has had the units arranged principally, if not entirely, within the return tubes, the units extending into the tubes from headers in the smoke box. The other type has had its units arranged primarily in the combustion or connecting chambers. The former type has given little difficulty in operation, but has provided only moderate degrees of .superheat when restricted to the weight and surface usually considered allowableon shipboard. The latter type of superheater has given relatively high 'superheat, but has suffered from the difliculty that it is apt to be damaged by overheating during the period of firing up 'the'boiler.

It is the principal object of my invention to provide a superheater arrangement for a Scotch type boiler adapted to give relatively high superheat without danger of being damaged in firing um I out in the appended claims} The invention itself, however, togetherwith its objects and advantages, will best beunderstood from the follow ing detailed description and. its accompanying drawings of a'superheater boiler exemplifying the invention and selected from a number of possible f embodiments thereof. .In'thefdrawings,

Fig. 1 is a plan View of a Scotch marine boiler flue l4 discharges rearwardly into a combustion or connecting chamber Ma which delivers the it products of combustion to a group of return tubes Mb, 14b, which discharge the gases from the furnace in flue l4 into the smoke-box or uptake l8. Similarly the flue l6 discharges into a combustion character 16a which delivers the of giving a high degree of super-' The novel features of myinvention are pointed gases received by it to agroup of return tubes 16b, 161), which discharge to the uptake it; It

will be noted that the chambers Ma and lfia are entirely distinct, their adjacent walls being separated by Water spaoeiil so that gases from one furnace do not mix with those from the other until reaching thesmoke-box or up-take.

In the smoke box I8. is a header 22 having a .centralpartition 24 and an inlet at one end and an outlet at the other. Steam entering header 22 flows out thru a group of superheater units into a second header 26 and thence through a second group of superheater units into the header 22 again, at a point on the other side of the partition 24. The steam then flows out of the header 22 to the point of use. As illustrated, the steam from header 22 first enters a group of superheater units 28, 28 which lie in the smoke tubes Mb. Preferably, each of the units 28 has a plurality of loops, each such loop in one of the tubes Mb. The units 28, however, preferably do not extend beyond the inner ends of tubes Mb or, if so, only to a minor extent. Units 28, therefore, are protected against overheating during firing up periods by the proximity of the water cooled tubes.

lflb. Units 28 deliver to the intermediate header 26 from which the steam enters a'group of superheater units 30, 30, each of which has an in going pipe 30a in one of the tubes leb and an outgoing pipe 30b in another such tube, the pipes 300. and 3% connecting at their inner ends with loops 30c, 300 in the chamber Ma, and of which there are preferably a plurality'for each unit 30. Loops 300 are arranged vertically in the chamber 16a and, in any event, they cannot pass thru tubes lBb. Breakable joints are therefore provided asv shown at 3|, 3| for connecting lengths 30a and 30b to loops 380.

The major portion of the surface of units 38 is in the chamber Hi where it'is subjected to high temperature gases when furnace flue I6 is in use. However, it is not necessary to heat such units except .when they have steam in them, because furnace flue I4 can be used exclusively during the firing up period. Both furnace flues, of course, are used when running and the steam is raised to'a high final temperature compared to that ordinarily used in marine installations due to the high rate of heat absorption in loops 300. Such loops, however, are not damaged because of thecooling effect of the steam under running conditions. r

What I claim is: s

1. The combination of a return tube boiler having, plurality of completely distinct and separate internal gas paths, each of which includes a furnace flue, a group of return tubes and a vertically extending chamber for connecting the furnace flue of a given gas path with its group of return tubes, groups or" superheater units each entirely within one of said gas paths, all the units in at least one of said paths lying substantially entirely within the return tubes of such path and the units in at least one of said paths having parts extending through some of the return tubes of such path and having a relatively large portion of their surface in the one of said connecting chambers.

2. The combination of a return tube boiler having a plurality of internal furnace flues, a plurality of separate combustion chambers one for each furnace flue and connected to receive the gases therefrom, groups of return tubes individual to said combustion chambers, a given furnace flue with its associated combustion chamber and groups of return tubes forming a separate gas path through, the boiler, groups of superheater units connected so that the steam flows from one group to another and each group being restricted to one of said gas paths, all. of the units in one gas path lying substantially entirely in the return tubes associated with such path and the units in another of said paths having parts extending through some of the return tubes associated with such path and having a relatively large portion of their surface in the combustion chamber of such path.

3. The combination of a return tube boiler having a plurality of separate gas paths therein and each such path including an internal furnace flue, a combustion chamber, anda group of returntubes, said chambers being spaced apart, a smoke box to which all the return flues deliver, a header in said smoke box having an inlet and a partition therein, a group of superheater elements connected to said header intermediate said inlet and said partition and lying substantially entirely within one group of return tubes, an intermediate header connected to receive steam from said and outlet portions lying within: said return: tubesin a gas path different from those of said firstmentioned group of units but having themajor portion of its heating surface in combustionchamber, said first header having a outlet for steam received from said second group of units.

1 JOHN A. BARNES. 

